Adaptive responses in uteroplacental metabolism and fetoplacental nutrient shuttling and sensing during placental insufficiency.

Glucose, lactate, and amino acids are major fetal nutrients. During placental insufficiency-induced intrauterine growth restriction (PI-IUGR), uteroplacental weight-specific oxygen consumption rates are maintained, yet fetal glucose and amino acid supply is decreased and fetal lactate concentrations are increased. We hypothesized that uteroplacental metabolism adapts to PI-IUGR by altering nutrient allocation to maintain oxidative metabolism. Here, we measured nutrient flux rates, with a focus on nutrients shuttled between the placenta and fetus (lactate-pyruvate, glutamine-glutamate, and glycine-serine) in a sheep model of PI-IUGR. PI-IUGR fetuses weighed 40% less and had decreased oxygen, glucose, and amino acid concentrations and increased lactate and pyruvate versus control (CON) fetuses. Uteroplacental weight-specific rates of oxygen, glucose, lactate, and pyruvate uptake were similar. In PI-IUGR, fetal glucose uptake was decreased and pyruvate output was increased. In PI-IUGR placental tissue, pyruvate dehydrogenase (PDH) phosphorylation was decreased and PDH activity was increased. Uteroplacental glutamine output to the fetus and expression of genes regulating glutamine-glutamate metabolism were lower in PI-IUGR. Fetal glycine uptake was lower in PI-IUGR, with no differences in uteroplacental glycine or serine flux. These results suggest increased placental utilization of pyruvate from the fetus, without higher maternal glucose utilization, and lower fetoplacental amino acid shuttling during PI-IUGR. Mechanistically, AMP-activated protein kinase (AMPK) activation was higher and associated with thiobarbituric acid-reactive substances (TBARS) content, a marker of oxidative stress, and PDH activity in the PI-IUGR placenta, supporting a potential link between oxidative stress, AMPK, and pyruvate utilization. These differences in fetoplacental nutrient sensing and shuttling may represent adaptive strategies enabling the placenta to maintain oxidative metabolism.NEW & NOTEWORTHY These results suggest increased placental utilization of pyruvate from the fetus, without higher maternal glucose uptake, and lower amino acid shuttling in the placental insufficiency-induced intrauterine growth restriction (PI-IUGR) placenta. AMPK activation was associated with oxidative stress and PDH activity, supporting a putative link between oxidative stress, AMPK, and pyruvate utilization. These differences in fetoplacental nutrient sensing and shuttling may represent adaptive strategies enabling the placenta to maintain oxidative metabolism at the expense of fetal growth.

Formal Parental Leave Policies and Trainee Well-Being in US Graduate Medical Education: A Systematic Review.

Background Variability in parental leave policies across graduate medical education (GME) programs in the United States complicates efforts to support resident wellness and identify best practices for resident well-being. Objective This review aims to assess how formal parental leave policies affect trainees' well-being, professional satisfaction, and performance during training. Methods A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) 2020 guidelines was conducted and registered on PROSPERO in May 2023. Databases searched included MEDLINE, Embase, and Cochrane Central. Studies that evaluated parental leave policies of US-based GME programs and their direct impact on residents and/or fellows were included. Studies were screened for inclusion by 2 independent reviewers, and any conflicts were resolved by a third author. Results Of 1068 articles screened, 43 articles met inclusion criteria. These studies highlighted that leave durations of less than 6 weeks were associated with higher rates of burnout and postpartum depression among trainees. There was no evidence that taking parental leave increased program attrition rate; however, 3 studies reported more than one-third of trainees extended training as a result of taking leave. Trainees who had more than 8 weeks of parental leave reported more successful breastfeeding 6 months out from delivery than those with less than 8 weeks of leave. Conclusions Extended parental leave, notably beyond 6 weeks, improved trainee well-being and professional satisfaction. Based on trainees' perspectives, ideal parental leave policies offer a minimum of 6 to 8 weeks of leave, with a formal and clearly written policy available.

Access to general obstetrics and gynecology care among Medicaid beneficiaries and the privately insured: a nationwide mystery caller study in the USA.

BACKGROUND: The mean wait time for new patient appointments has been growing across specialties, including obstetrics and gynecology, in recent years. This study aimed to assess the impact of insurance type (Medicaid versus commercial insurance) on new patient appointment wait times in general obstetrics and gynecology practices. METHODS: A cross-sectional study used covert mystery calls to general obstetrician gynecologists. Physicians were selected from the American College of Obstetricians and Gynecologists directory and stratified by districts to ensure nationwide representation. Wait times for new patient appointments were collected and analyzed. RESULTS: Regardless of insurance type, the mean wait time for all obstetrician gynecologists was 29.9 business days. Medicaid patients experienced a marginally longer wait time of 4.8% (Ratio: 1.048). While no statistically significant difference in wait times based on insurance type was observed (P=0.39), the data revealed other impactful factors. Younger physicians and those in university-based practices had longer wait times. The gender of the physician also influenced wait times, with female physicians having a mean wait time of 34.7 days compared to 22.7 days for male physicians (P=0.03). Additionally, geographical variations were noted, with physicians in American College of Obstetricians and Gynecologists District I (Atlantic Provinces, CT, ME, MA, NH, RI, VT) having the longest mean wait times and those in District III (DE, NJ, PA) the shortest. CONCLUSIONS: While the type of insurance did not significantly influence the wait times for general obstetrics and gynecology appointments, physician demographic and geographic factors did.

Temporal discounting correlates with directed exploration but not with random exploration.

The explore-exploit dilemma describes the trade off that occurs any time we must choose between exploring unknown options and exploiting options we know well. Implicit in this trade off is how we value future rewards - exploiting is usually better in the short term, but in the longer term the benefits of exploration can be huge. Thus, in theory there should be a tight connection between how much people value future rewards, i.e. how much they discount future rewards relative to immediate rewards, and how likely they are to explore, with less 'temporal discounting' associated with more exploration. By measuring individual differences in temporal discounting and correlating them with explore-exploit behavior, we tested whether this theoretical prediction holds in practice. We used the 27-item Delay-Discounting Questionnaire to estimate temporal discounting and the Horizon Task to quantify two strategies of explore-exploit behavior: directed exploration, where information drives exploration by choice, and random exploration, where behavioral variability drives exploration by chance. We find a clear correlation between temporal discounting and directed exploration, with more temporal discounting leading to less directed exploration. Conversely, we find no relationship between temporal discounting and random exploration. Unexpectedly, we find that the relationship with directed exploration appears to be driven by a correlation between temporal discounting and uncertainty seeking at short time horizons, rather than information seeking at long horizons. Taken together our results suggest a nuanced relationship between temporal discounting and explore-exploit behavior that may be mediated by multiple factors.